In the field of nonwoven materials, there has been a continuing need for materials having high degree of flexibility and elasticity and which may be manufactured at a low cost. In particular, there is a need for an elastic material having a low initial load tension, low stress relaxation, low hysteresis and high recoverable energy. This need has persisted in spite of the fact that such materials could readily be utilized in the manufacture of a wide variety of garments of both the disposable type, such as disposable diapers, or the durable type, such as pants, dresses, blouses and sporting wear, for example, sweatsuits. Further, such materials could also be utilized in, for example, upholstery, drapery, liner and insulation applications. The traits of low initial load tension, low stress relaxation, low hysteresis and high recoverable energy are particularly desirable characteristics for materials used in these areas because articles manufactured from such materials may be easily put on the body of the wearer or any item, such as a fixed frame, around which the materials may be wrapped. Those traits are also very useful because articles manufactured from such materials are able to closely conform to the body of a wearer or any item and repeatedly extend and retract without sagging.
Elastic nonwoven webs of fibers have been formed from blends of styrene-poly(ethylene-butylene)-styrene elastomeric block copolymers with other materials such as, for example, polyolefins and tackifying resins to improve processing and/or bonding. While improving the processing and/or bonding properties of the elastic webs, such additives may, in certain situations, have an adverse affect on the elastic properties of the material. For example, elastic block copolymers blended with large amounts of a polyolefin and/or hydrocarbon resin may have poor stress relaxation properties and stress-strain tests of such materials show significant hysteresis.